I think it is a great point about the percentage that use the scholarship money.
When people say, "My son can go to college anytime." I respond with, "Yes, but your son will never again be an 18 year old college freshman." Those of us who went to college understand the experience we had at 18 - 21 versus those students we knew who were 25+.
My son will not have to make this decision as his ability doesn't put him in the position, but if he did, I would counsel him to go to college. Even if the bonus is huge (800K+), playing the percentages, he would never see a MLB paycheck and never use the MLB scholarship money. At that point, what would his earning potential be? Lately, I've seen college lists about mid-career earning potential. It would be interesting to see some data on drafted and signed baseball players vs. university graduate. I'll bet it would open some eyes.